Micron Phase Angle Meter

Standard Features

• Measures phase angle between two waveshapes of identical period.
• Resolution of 1º, 0.1º or 0.01º
• 0.01% accuracy at AC line frequency
• Inputs from 12 mV p-p to 250 Vac
• Trigger on positive or negative pulse edges.
• Frequency from 0.005 Hz to 10 kHz
• 6-digit red or green LED display
• Isolated 5, 10 or 24 Vdc excitation output to power sensors.
• Universal AC power, 85-264 Vac
• External controls for reset, meter hold and decimal points
• NEMA 4X, 1/8 DIN case
  
• Options:
• Low voltage power: 10-48 Vdc or 12-30 Vac
• Dual or Quad relays: Form C contact or Form A solid state
• Analog output: Isolated, 4-20 mA, 0-20 mA, 0-10V, -10 to +10V
• Serial communications: RS232, RS485, Modbus RS485, USB, USB-to-RS485 converter
• Certified to UL 61010C-1 (UL mark), EN 61010-1 (CE mark), and RoHS

Description

Phase Angle Measurement

Phase angle indicates the lead or lag in degrees from
-180º to +180º between two periodic signals of the same period. In the illustration to the right, phase angle is 360*P1/P.

The Micron phase angle meter provides exceptionally fast response and high accuracy at low frequencies such as AC line frequency. A display from -180º to +180º is obtained by timing the rising edge of one channel and the falling edge of the other channel, and programming a 180º offset. A resolution of 1º, 0.1º or 0.01º is selectable. Accuracy is 0.01% up to 100 Hz, 0.1% at 1 kHz, and 1% at 10 kHz.

Phase angle measurement requires that two signals with identical periods be applied to Channels A and B. One of the signals is typically an AC voltage up to 250 Vac, and the other signals is the voltage developed across a current shunt driven by a 5A current transformer. Both signals need to be mutually isolated. For best accuracy, both signals should have the same amplitude which should be larger that 1V, and the trigger level should be set at near the zero crossing of each waveshape at 12 mV.

Phase angle is determined by timing crystal clock pulses over a specified gate time, which is selectable from 10 ms to 199.99 s. By selecting the minimum gate time of 10 ms, the update rate can be up to 20/s for 50/60 Hz AC line frequency. Improved accuracy is obtained by making the gate time long enough so that multiple cycles are averaged.

Universal Pulse Signal Conditioner

The Micron Phase Angle Meter uses the Extended counter main board and the FR dual-channel signal conditioner board, which is jumpered for AC signals from 12 mV to 250 Vac. Jumper and digital noise filter selections provide optimum operation for different noise conditions.

Other Features & Options

Plug-in isolated analog output, dual or quad setpoint controller, and RS232/485 serial data I/O boards can upgrade the Micron from a stand-alone monitor to system interface and control. The 1/8 DIN case of Micron meters and counters meets NEMA 4X (IP-65) standards from the front for high pressure wash-down when panel mounted.

Applications

Synchronization of two motor generators requires that the two frequencies be identical, that the lines be in phase, and that the line voltages be close to each other. In this illustration, a single Micron dual channel counter measures both frequencies to six-figure accuracy in a few line cycles. Another Micron dual channel counter measures phase angle to 0.1º resolution. Two Micron AC RMS Voltmeters, which offer ranges of 200.00 V and 600.0 V, are used to display the two RMS voltage to 0.1% accuracy.